Expandable vertebral implant

ABSTRACT

A joint spacer therapeutically maintains separation of bones of a joint. A carriage is slideably retained within the frame and has at least one ramped surface. An actuator screw is threadably engaged with the frame, and rotatably connected to the carriage, to cause the carriage to slideably move within the frame when the actuator screw is rotated. First and second endplates engage the bones of the joint, and each has at least one ramped surface that is mateable with the ramped surface of the carriage, whereby when the carriage is slideably moved by rotation of the actuator screw, the endplates ramped surface slides against the carriage ramped surface to cause the endplates to move along an axis transverse to the longitudinal axis of the frame, to increase the height of the spacer. Piercing elements are connected to the carriage to pierce bone of the joint when the carriage is moved.

CROSS REFERENCE TO RELATED APPLICATIONS

This Patent Application is a continuation-in-part application of U.S.patent application Ser. No. 13/837,452 filed on Mar. 15, 2013, which isa continuation-in-part of U.S. patent application Ser. No. 13/711,204,filed on Dec. 11, 2012, the entire contents of each of which areincorporated by reference.

FIELD OF THE INVENTION

This invention relates to stabilizing adjacent vertebrae of the spine byinserting an intervertebral spacer, and more particularly, anintervertebral spacer that is adjustable in height, has plates forfixation, and uses anchors to fasten the spacer into a patient.

BACKGROUND OF THE INVENTION

Bones and bony structures are susceptible to a variety of weaknessesthat can affect their ability to provide support and structure.Weaknesses in bony structures have numerous potential causes, includingdegenerative diseases, tumors, fractures, and dislocations. Advances inmedicine and engineering have provided doctors with a plurality ofdevices and techniques for alleviating or curing these weaknesses.

In some cases, the spinal column requires additional support in order toaddress such weaknesses. One technique for providing support is toinsert a spacer between adjacent vertebrae.

SUMMARY OF THE INVENTION

In accordance with the disclosure, a joint spacer for therapeuticallymaintaining a separation of bones of a joint, comprises a frame havingdistal and proximal ends defining a longitudinal axis extendingtherebetween; a carriage slideably retained within the frame and havingat least one ramped surface, the carriage further including a threadedportion; an actuator screw threadably engaged with the frame, theactuator screw configured to bear against the carriage to cause thecarriage to slideably move within the frame when the actuator screw isrotated; a first endplate configured to engage a first bone of thejoint, and having at least one surface mateable with the at least onecarriage ramped or a feature surface, whereby when the carriage isslideably moveable by rotation of the actuator screw, the at least oneendplate ramped surface slides against the at least one carriage rampedsurface to cause the first endplate to move along an axis transverse tothe longitudinal axis to increase a height of the spacer; and a secondendplate configured to engage a second bone of the joint.

In one embodiment thereof, the carriage includes at least two rampedsurfaces, and the second endplate includes at least one ramped surfacemateable with at least one of the at least two ramped surfaces of thecarriage, whereby when the carriage is slideably moved by rotation ofthe actuator screw, the at least one second endplate ramped surfaceslides against the at least one additional carriage ramped surface tocause the second endplate to move along an axis transverse to thelongitudinal axis to increase a height of the spacer.

In other embodiments thereof, the first endplate is configured to abutthe frame as the first endplate is moved along an axis transverse to thelongitudinal axis, whereby the first endplate moves substantially onlyalong an axis transverse to the longitudinal axis; the first endplateincludes at least one aperture through which a fastener may pass tosecure the first endplate to a bone of the joint; the spacer furtherincludes a blocking mechanism to prevent backing out of a fastenerpassed through the first endplate; and the first endplate includes oneor more projections configured to engage bone of the joint when theimplant is positioned between bones of the joint.

In further embodiments thereof, at least one of the first and secondendplates is composed of two interconnected portions of dissimilarmaterials; one of the dissimilar materials is metallic and includes atleast one aperture through which a fastener may be passed to attach theimplant to a bone of the joint; and one dissimilar material ispolymeric, and another dissimilar material is metallic. Other possiblematerials include carbon fiber, bone, etc.

In yet further embodiments thereof, the actuator screw includes a flange(or a pocket or other feature), and the carriage includes a flange (orc-clip or other feature) rotatably mateable with the actuator screwflange; the spacer further includes a thrust washer interposed betweenthe actuator screw and the carriage; the spacer further includes apolymeric material configured to press against the actuator screw toreduce a potential for unintended rotation of the actuator screw; andthe spacer further includes a plate having at least one aperture sizedand dimensioned to receive an elongated fastener for fastening thespacer to bone of the joint, the plate being releaseably detachable fromthe spacer to reduce an profile of the spacer during insertion of thespacer into the body, the plate attached to the spacer inside the body.

In other embodiments thereof, the plate and the frame include matingportions of a twist-lock connector operable to connect the plate to theframe when the spacer is inside the body; the plate and the frameinclude mating portions of a snap-fit interference connector operable toconnect the plate to the frame when the spacer is inside the body oroutside; the plate includes hinged portions, the hinged portionsfoldable to reduce a profile of the plate during insertion of the plateinto the body; the at least one surface mateable with the at least onecarriage ramped surface is at least one ramp; the at least one carriageramp is disposed upon at least one cam, the cam rotatable to bear the atleast one carriage ramp against the at least one surface of the firstendplate; the first endplate includes a rotatable portion having firstand second transverse axes of different lengths; and the rotatableportion is passable through an interior of the spacer.

In other embodiments thereof, the first endplate includes an aperturesized and dimensioned to receive an elongated fastener operable to passthrough the aperture to affix the spacer to bone of the joint, theaperture movable with the first endplate as the first endplate is movedalong the axis transverse to the longitudinal axis; and the firstendplate includes a first portion having at least one aperture throughwhich a fastener may pass to secure the first endplate to a bone of thejoint, and a second portion configured to support bone of the joint, thefirst and second portions mutually connected by a dovetail or other typeof connection.

In additional embodiments thereof, the spacer further includes arotatable plate having at least two apertures through each of which afastener may pass to secure the spacer to a bone of the joint, therotatable plate rotatable after the spacer has been implanted within thebody, to overlie the at least two apertures with bone of the joint; thespacer further includes a rotatable plate having at least two aperturesthrough each of which a fastener may pass to secure the spacer to a boneof the joint, the rotatable plate rotatable after the spacer has beenimplanted within the body, to overlie the at least two apertures withbone of the joint; the spacer further includes at least one rotatableplate having an aperture through which a fastener may pass to secure thespacer to a bone of the joint, the rotatable plate rotatable after thespacer has been implanted within the body, to overlie the aperture withbone of the joint; and the spacer further includes at least two platesrotatably connectable to the spacer, each plate slidably connected tothe other by a dovetail joint, each plate having at least one aperturethrough which a fastener may pass to secure the spacer to bone of thejoint, the plates rotatable after the spacer has been implanted withinthe body, and each of the at least two plates slideable with respect tothe other, to overlie the aperture of each plate with bone of the joint.

In yet further embodiments thereof, at least one of the carriage rampedsurfaces is operative to push a piercing element through an aperture inthe first endplate, the piercing element operative to pierce bone of thejoint to secure the spacer within the body; the spacer further includesa bone screw having bone engaging threads and gear teeth, and theactuator screw including gear teeth engageable with the gear teeth ofthe bone screw, the actuator screw thereby rotated when the bone screwis threaded into bone of the joint; the spacer further includes a platehaving an aperture through which a fastener may be passed to connect thespacer to bone of the joint, the plate including a dovetail portion; andthe first endplate including a dovetail portion mateable with thedovetail portion of the plate, the plate and the first endplate therebysecurely connectable to each other; and the spacer further includes achannel formed within the first endplate, the channel sized anddimensioned to receive an elongate portion of a fastener operative tosecure the spacer within the body.

In other embodiments thereof, the spacer further includes at least oneelongate rotatable deployer pivotally connected to the frame; at leastone piercing element connected to the deployer, the at least onepiercing element operable to pierce bone of the joint when the rotatabledeployer is rotated within the body; the at least one piercing elementis pivotally connected to the deployer to thereby enter bone of the bodyat a desired angle relative to a plane of the first endplate; the atleast one rotatable deployer rotates about a common axis with respect tothe actuator screw; the at least one rotatable deployer rotates when theactuator screw is rotated; and the at least one rotatable deployerrotates independently of the actuator screw.

In yet further embodiments thereof, the first endplate is pivotallyconnected to the frame; the first endplate pivots about the pivotalconnection, about an axis extending transverse to the longitudinal axis;and the first endplate is connected to the frame to allow roll, pitch,and yaw movement of the first endplate with respect to the frame.

In another embodiment of the disclosure, a joint spacer fortherapeutically maintaining a separation of bones of a joint, comprisesa frame having distal and proximal ends defining a longitudinal axisextending therebetween; a carriage slideably retained within the frameand having at least one ramped surface, the carriage further including aflange; an actuator screw threadably engaged with the frame, theactuator screw including a flange rotatably mateable with the carriageflange, whereby the carriage is slideably moved when the actuator screwis rotated; a first endplate configured to engage a first bone of thejoint, and having at least one ramped surface mateable with the at leastone carriage ramped surface, whereby when the carriage is slideablymoved by rotation of the actuator screw in a first direction, the atleast one endplate ramped surface slides against the at least onecarriage ramped surface to cause the first endplate to move along anaxis transverse to the longitudinal axis to increase a height of thespacer; and a second endplate configured to engage a second bone of thejoint.

In various embodiments thereof, when the actuator screw is rotated in anopposite, second direction, the at least one endplate ramped surface isslideable against the at least one carriage ramped surface to cause thefirst endplate to move along an axis transverse to the longitudinal axisto decrease a height of the spacer; the first endplate includes ametallic portion having an aperture through which a fastener may bepassed for connecting the implant to body tissue, the first endplatefurther having a polymeric portion connected to the metallic portion,the polymeric portion sized and dimensioned to support a bone of thejoint; the frame and the first endplate include mateable dovetailedportions configured to maintain an orientation of the first endplate andthe frame when the first endplate is positioned proximate the frame.

In another embodiment of the disclosure, a method for therapeuticallymaintaining a separation of bones of a joint, comprises inserting aspacer between bones of the joint, the spacer including—a frame havingdistal and proximal ends defining a longitudinal axis extendingtherebetween; a carriage slideably retained within the frame and havingat least one ramped surface, the carriage further including a flange; anactuator screw threadably engaged with the frame, the actuator screwincluding a flange rotatably mateable with the carriage flange, wherebythe carriage is slideably moved when the actuator screw is rotated; afirst endplate configured to engage a first bone of the joint, andhaving at least one ramped surface mateable with the at least onecarriage ramped surface, whereby when the carriage is slideably moved byrotation of the actuator screw in a first direction, the at least oneendplate ramped surface slides against the at least one carriage rampedsurface to cause the first endplate to move along an axis transverse tothe longitudinal axis to increase a height of the spacer; and a secondendplate configured to engage a second bone of the joint; the spacerinserted when the first endplate is positioned proximate the frame; andslideably moving, by rotation of the actuator screw, the at least oneendplate ramped surface against the at least one carriage ramped surfaceto cause the first endplate to move along an axis transverse to thelongitudinal axis to increase a height of the spacer to maintain aseparation of bones of the joint.

In yet further embodiments thereof, a spacer consistent with the presentdisclosure may include one or more fasteners (in addition to or as analternative to a bone screw) configured to anchor or fasten the spacerto the patient. The fastener or anchor, for example, may be insertedinto body tissue of the patient. The anchor may be configured to becurved and contain sharp edges to pierce the bone of the patient. Theanchor may be straight or helical and may also contain serrated edges toaid in insertion into the patient and restricting expulsion of theanchors from the bone.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings, in which:

FIG. 1 depicts a perspective view of a spacer in accordance with thedisclosure, including bone fasteners, the spacer in a reduced height, orcompressed configuration;

FIG. 2 depicts the spacer of FIG. 1, in an increased height, or expandedconfiguration;

FIG. 3 depicts a front view of the spacer of FIG. 1;

FIG. 4 depicts a front view of the spacer of FIG. 2;

FIG. 5 depicts a cross-section taken through a center of the spacer ofFIG. 2;

FIG. 6 depicts a top view of the spacer of FIG. 1;

FIG. 7 is a diagram of a possible implantation location in the body, forthe spacer of FIG. 1;

FIG. 8 depicts an embodiment of a spacer in accordance with thedisclosure, including a fixation plate that is removeably connectable toa remainder of the spacer, the fixation plate shown removed;

FIG. 9 depicts a connector for connecting the fixation plate to aremainder of the spacer, with respect to FIG. 8;

FIG. 10 depicts the spacer of FIG. 8, the fixation plate attached;

FIG. 11 depicts a reverse side of the spacer of FIG. 10;

FIG. 12 depicts a front view of the spacer of FIG. 10;

FIG. 13 depicts a side view of an embodiment of a spacer in accordancewith the disclosure, the spacer including a detached fixation platehaving a snap-fit attachment;

FIG. 14 depicts the spacer of FIG. 13, the fixation plate snap-fit intoattachment;

FIG. 15 depicts the fixation plate of FIG. 13;

FIG. 16 depicts a hinged fixation plate in accordance with theembodiment of FIG. 13;

FIG. 17 depicts the hinged fixation plate of FIG. 16, the hingedportions folded, and further showing barbs upon the hinged portion;

FIG. 18 depicts an embodiment of a spacer in accordance with thedisclosure, including cams operative to increase a height of the spacer,the spacer in a reduced height configuration;

FIG. 19 depicts the spacer of FIG. 18, the cams actuated to increase aheight of the spacer;

FIG. 20 depicts an embodiment of a spacer in accordance with thedisclosure, the spacer including rotatable endplate portions;

FIG. 21 depicts an end view of the spacer of FIG. 20;

FIG. 22 depicts the spacer of FIG. 21, the rotatable endplate portionrotated;

FIG. 23 depicts an embodiment of a spacer in accordance with thedisclosure, having endplates that translate together with endplates, asendplates are moved to increase a height of the spacer;

FIG. 24 depicts the spacer of FIG. 23, the spacer expanded to have anincreased or expanded height;

FIG. 25 depicts a side view of an embodiment of a spacer in accordancewith the disclosure, the spacer having connectable fixation portions andendplate support portions;

FIG. 26 depicts a cross-section of the spacer of FIG. 25;

FIG. 27 illustrates an embodiment of a spacer including connectablefixation portions and endplate support portions, the portionsconnectable by a dovetailed connection;

FIG. 28 depicts a cross-section of the device of FIG. 27;

FIG. 29 depicts an embodiment of a spacer of the disclosure, including arotatable fixation plate;

FIG. 30 depicts the spacer of FIG. 29, the fixation plate rotated;

FIG. 30A depicts an embodiment of a spacer of the disclosure, includingtwo rotatable fixation plates, rotated to a deployment position;

FIG. 31 depicts an embodiment of a spacer of the disclosure includingtwo rotatable fixation portions connected by a sliding dovetailconnection;

FIG. 32 depicts the spacer of FIG. 31, the fixation portions relativelydisplaced and rotated;

FIG. 33 depicts a cross-section the spacer of FIG. 31;

FIG. 34 depicts an embodiment of a spacer of the disclosure, includingdeployable piercing elements;

FIG. 35 depicts the spacer of FIG. 34, the piercing elements deployed;

FIG. 36 depicts an embodiment of a spacer of the disclosure, including abone fixation device having gear teeth mateable with gear teeth of anendplate actuator screw;

FIG. 37 depicts the spacer of FIG. 36, the bone fixation device deployedto engage bone, and to increase a height of the spacer;

FIG. 38 depicts an embodiment of a spacer of the disclosure, including adovetail connection between a fixation portion, and a bone endplatesupport portion;

FIG. 39 depicts the fixation portion of the spacer of FIG. 38;

FIG. 40 depicts the bone endplate support portion of the spacer of FIG.38;

FIG. 41 depicts an embodiment of a spacer in accordance with thedisclosure, including channels in endplate portions;

FIG. 42 depicts a top view of an embodiment of a spacer in accordancewith the disclosure having deployment arms rotatably supporting piercingelements;

FIG. 43 depicts a cross section of the spacer of FIG. 42;

FIG. 44 depicts the spacer of FIG. 43, the piercing elements deployed;

FIG. 45 depicts an embodiment of a spacer in accordance with thedisclosure, including a deployment arm having a common axis with anactuator screw;

FIG. 46 depicts a cross section of the spacer of FIG. 45;

FIG. 47 depicts the spacer of FIG. 46, the piercing elements deployed;

FIG. 48 illustrates an alternative spacer in accordance with FIG. 45,the deployment arm independently rotatable; and

FIG. 49 illustrates an embodiment of a spacer in accordance with thedisclosure, an endplate pivotable about a transverse axis.

FIG. 50 illustrates an exploded view of an alternative spacer accordingto some embodiments.

FIG. 51 illustrates a top perspective view of the alternative spacer ofFIG. 50 with upper endplate removed.

FIG. 52 illustrates a side cross-sectional view of the alternativespacer of FIG. 50.

FIG. 53 illustrates a different cross-sectional view of the alternativespacer of FIG. 50.

FIGS. 54A and 54B illustrate a rear view of the alternative spacer ofFIG. 50.

FIG. 55 illustrates a top cross-sectional view of the alternative spacerof FIG. 50.

FIG. 56 illustrates a close-up cross-sectional view of the actuationmember and translation member of the alternative spacer of FIG. 50.

FIG. 57 illustrates an alternative spacer consistent with the presentdisclosure containing anchors.

FIG. 58 illustrates a top view of the alternative spacer of FIG. 57.

FIG. 59 illustrates a side view of the alternative spacer of FIG. 57.

FIG. 60 illustrates a different view of the alternative spacer of FIG.57.

FIG. 61A illustrates an exemplary anchor consistent with the presentdisclosure.

FIG. 61B illustrates an exemplary anchor consistent with the presentdisclosure.

FIG. 61C illustrates an exemplary anchor consistent with the presentdisclosure.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments are disclosed herein; however, it isto be understood that the disclosed embodiments are merely examples andthat the systems and methods described below can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present subject matter in virtually anyappropriately detailed structure and function. Further, the terms andphrases used herein are not intended to be limiting, but rather, toprovide an understandable description of the concepts.

The terms “a” or “an”, as used herein, are defined as one or more thanone. The term plurality, as used herein, is defined as two or more thantwo. The term another, as used herein, is defined as at least a secondor more. The terms “including” and “having,” as used herein, are definedas comprising (i.e., open language).

With reference to FIGS. 1-7, spacer 100 is operative, when positionedbetween adjacent bones of a joint, such as for example vertebrae 10, 12(shown in FIG. 7), to stabilize a joint formed between adjacentvertebrae. Spacer 100 has a collapsed state or height, illustrated inFIGS. 1 and 3, and an expanded state or height, illustrated in FIGS. 2,4 and 5. Spacers 100 of the disclosure may be inset into theintervertebral disc space at a collapsed height, and then expand axially(superior/inferior) to restore height loss in the disc space. Spacer 100provides distraction as well as achieves optimal separation of adjacentvertebrae, or disc height restoration. When inserted in a collapsedstate, Spacers 100 have a reduced height profile which reduces adverseimpact to tissue adjacent to and within the joint space duringinsertion, while presenting the least visually blocking or physicallyobstructing profile. Spacer 100 may be reduced in height afterimplantation, for example by inserting a tool through a minimalincision, to perform a therapeutic height adjustment. Spacer 100 mayalso be reduced in height to a compressed configuration, to facilitateremoval from the body. Spacer 100 supports the cortical rim of adjacentvertebrae, and distributes forces across the vertebra, therebymaximizing vertebral endplate preservation.

Spacer 100 includes two separable endplates 110, 112. A surface 114 ofan endplate 110, 112 can be provided with teeth or other projections 116which can penetrate body tissue to reduce a likelihood of migration ofspacer 100 after implantation. Spacer 100 is further secured with one ormore fasteners, such as bone screws 300, which pass through an adapter,such as bone screw socket 118 within spacer 100, and into body tissue ofthe patient. In the embodiment illustrated in FIGS. 1-5, two sockets 118for two bone screws are provided, although one or more than twofasteners and fastener adapters, may be provided. Bone screws 300 can beretained in connection with spacer 100 by blocking fasteners 120. Bonescrew 300 can be a polyaxial screw, and sockets 118 correspondinglyshaped, whereby bone screw 300 may be inserted into body tissue at anoptimal angle with respect to spacer 100, whereby optimal purchase maybe obtained, or certain body tissue may be avoided.

Endplates 110, 112 are moveably connectable to an actuator 150 operableto change a relative relationship of endplates 110 and 112. Actuator 150includes a frame 152 rotatably supporting an actuator screw 154, and amoveable carriage 156. As actuator screw 154 rotates within frame 152,carriage 156 slides within frame 152, driven by cooperation betweenthreads 158 upon actuator screw 154, and mating threads 160 within frame152. An implantation tool engagement surface 330 may be provided upon orwithin spacer 100, configured to receive a tool to enable securemanipulation of spacer 100 during implantation or removal from the body.

In the embodiment of FIGS. 1-6, endplates 110 and 112 are formed in twoconnected portions, including a portion 122, 122A which can bepolymeric, for example PEEK, and a fixation portion 124, 124A, which canbe metallic, for example titanium, although other materials may be used.For example, material used for fixation portion 124 should withstand thebending forces exerted by a fastener, for example bone screw 300,passing therethrough. In contrast, endplate material advantageouslyresiliently withstands a pressure applied by weight of the body. In thisregard, both materials could also be polymeric, for example, but ofdifferent types of polymer.

The portions 122, 124 or 122A and 124A are joined in the embodimentshown by screws, a mechanical interlock, adhesive, or other fasteners,possibly in combination, as explained further herein. Metallic portions124, 124A can provide greater strength for portions of spacer 100 whichare under relatively greater stress, for example portions through whicha fastener may pass to anchor spacer 100 within the body. While portions122, 122A, 124, 124A are described as polymeric or metallic, it shouldbe understood that other materials may be used, and that the portionscan be of similar or dissimilar materials, as described further herein.

With reference to FIGS. 1 and 3, it may be seen that spacer 100 is in acompressed state, having a lower height relative to an expanded state,as shown in FIGS. 2 and 4. A functioning of device 100 may be bestunderstood with reference to FIG. 5, which is a cross-section throughthe center of spacer 100. Endplates 110 and 112 are provided with ramps164, sized to slidingly receive ramps 168 disposed upon carriage 156.While three mating ramps 164, 168 are illustrated for each endplate 110,112, it should be understood that one, two, or more than three sets oframps 164, 168 may be provided. Mating ramps 164, 168 operate to enablea reduction or increase in height by sliding against each other asactuator screw 154 is rotated. Interlocking flanges 204, 204A rotatablycouple actuator screw 154 and carriage 156, whereby actuator screw mayrotate and advance or retard in connection with frame 152, concomitantlyadvancing or retarding carriage 156 along a longitudinal axis of spacer100 extending from a distal end 186 and a proximal end 182 of frame 152.A reduction in height is further fostered by a pressure exerted by bodytissue.

As may further be seen in FIG. 5, ramps 164 can include channels 164Awithin endplates 110, 112, and ramps 168 may include dovetail portions168A which extend into ramps 164. By projecting a dovetail portion 168Aof ramp 168 into channels 164A, endplates are moveably affixed tocarriage 156. Dovetail portions 168A and channels 164A may furthersupport a predetermined relative orientation of endplates 110, 112 whenin a compressed or expanded configuration, while they are beingexpanded, and when spacer 100 is inserted and removed from the body. Itshould further be understood that a relative orientation of endplates110, 112 may be substantially parallel, or may be non-parallel, forexample to produce an effective lordosis. Further, planes defined by aninterior portion of endplates 110, 112 may be relatively parallel, butbone contacting surfaces may be relatively non-parallel.

Carriage 156 is alternatively or further supported by frame 152 bylateral engagement means, in the embodiment shown there are two supportscrews 174 engaged with carriage 156, and passable through respectivechannels 176 formed in frame 152.

A hex driver (not shown) is inserted into engagement with an end ofactuator screw 154 at a proximal end 182 of frame 152. As actuator screw154 is turned, distal end 172 bears against a thrust washer 184, and anend portion of frame 152. As actuator screw 154 rotates in onedirection, carriage 156 is driven along actuator screw by interaction ofthreads 158 and 160 and flanges 204, 204A. As carriage 156 moves,endplates 110, 112 are urged to move along ramps 168, and 168A ifpresent, causing endplates 110, 112 to thereby moving relatively apart,and to increase a height of spacer 100. Endplates 110, 112 are movedrelative to carriage 156 by abutting against an end portion 186 of frame152. End portion 186 can include an internal ramped surface 170 mateablewith a ramp 168, as shown in this embodiment, thereby providingadditional stability in an expanded configuration.

In a given orientation, one of endplate 110 and 112 is an upper endplatewith respect to an orientation in a standing patient. However, spacer100 may, in some embodiments, be implantable in either of oppositeorientations, and therefore designations of upper and lower are providedfor ease of understanding, only. It should further be understood thatonly one of endplate 110, 112 may be moveable with respect to the other.For example, in one embodiment, ramps 168, 168A may not be provided, andendplate 112 may be attached to frame 152.

FIG. 7 illustrates a spacer 100 of the disclosure implanted betweenadjacent vertebrae 10, 12. Frame 152 defines a distal or leading end 186which is inserted first into the body, and a proximal or trailing end182 which passes last into the body, the distal and proximal endsdefining a longitudinal axis extending therebetween. Spacer 100 can beinserted into the body, and into a position between vertebrae, usingminimally invasive methods, for example using a small incision, andspacer 100 may be passed through a cannula or other structure whichmaintains a pathway through body tissue. Spacer 100 may be inserted intothe spinal column through any approach, including anterior,anterolateral, lateral, posterolateral, or posterior. A portion of thedisc annulus, and nucleus pulposus may be removed in order to form aspace into which spacer 100 may be inserted.

Spacer 100 can be inserted when configured to have a lower heightprofile, as shown in FIGS. 1 and 3, whereby an extent of distraction ofbody tissue may be reduced during insertion. Moreover, to the extentthat spacer 100 is used to open a pathway towards an implantation site,trauma to adjacent tissue is reduced relative to inserting a spacerhaving a final height profile. Once spacer 100 is positioned betweenadjacent vertebrae, actuator screw is rotated by a tool. The tool may bepositioned entirely within the body, or can extend from in interior ofthe body to outside the body, for example having a driving tip at oneend and having a handle at an opposite end, with a shaft extending intothe body between each end.

Once actuator screw 154 has been rotated to separate endplates 110, 112a desired amount, the tool is removed. At this point, actuator screw 154may be secured in place, for example using a mechanical block, or anadhesive, to prevent unintended rotation of actuator screw 154. Ascarriage 156 is slideably moved by rotation of actuator screw 154, ramps164, 168 of endplates 110, 112 slide against each other, to cause theendplate to move along an axis transverse to the longitudinal axis ofthe frame, to increase a height of the spacer. Rotation of actuatorscrew 154 in an opposite direction causes movement along an axistransverse to the longitudinal axis of the frame to decrease a height ofthe spacer.

In FIG. 6, it may be seen that spacer 100 has an elongated, narrowprofile, facilitating insertion from a lateral approach. Bone ingrowthapertures 332 may be provided, to promote the ingrowth of bone of thepatient to further stabilize spacer 100, or to achieve fusion, shouldthat be a therapeutic objective.

Polymeric insets, or a polymeric square nut, for example PEEK, can beprovided, engageable with threads 158 or other portion of actuator screw154, to provide additional friction to prevent height loss under load,particularly under cyclic loading. Similarly, once bone screws 300 havebeen inserted, blocking elements 196 may be rotated to extend over anend of bone screw head 302, preventing screw 300 from backing out. Toenable insertion of bone screw 300, a notched portion 196A is formed inblocking element, and which may be rotated into a position adjacentaperture 118. A similar mechanical block (not shown) may be provided foractuator screw 154.

With reference to the figures, it may be seen that sockets 118 move withendplate 110 or 112, as spacer 100 expands to a final height, wherebysockets 118 overlie cortical bone of vertebrae 10, 12 after spacer 100is expanded.

In an embodiment, spacer 100 of the disclosure provides an actuator thattranslates relative to the body by means of a threaded actuator screw154. Ramps 168, 168A on a carrier 152 mate with ramps 164, 164A onendplates 110, 112. Linear translation of carriage 152 causes endplates110, 112 to expand spacer 100 along an S/I axis with respect to thebody.

In one embodiment, two bone screws 300 are used to provide fixation intoadjacent vertebral bodies, a screw extended from each of endplates 110and 112. Spacer 100 can thus be narrow, to therapeutically fit betweenvertebrae when inserted from a lateral approach. However, one screw, ormore than two screws 300 may be used. Bone screws 300 can have sphericalor otherwise curved heads, facilitating insertion at a desired angle, ormay be provided to mate with socket 118 in a fixed orientation, forexample depending on a diameter of a neck portion of screw 300. Cam typeblocking fasteners 196 can be used to block bone screws 300 from backingout after being inserted.

Referring now to FIGS. 8-12, a spacer 100A is similar to spacer 100,however a fixation plate 210 is rotatably fastened to a collar 212extending from frame 152A. The collar includes an interlock 214, in theexample shown a twist-lock connector, although any means of mechanicallyfastening fixation plate 210 to the remainder of spacer 100A may beused, provided that fixation plate 210 and actuation screw 154 may berotated as described herein. Fixation plate 210 enables spacer 100A tobe inserted into the body with fixation plate 210 rotated to have alongitudinal axis aligned with a transverse axis of spacer 100A, wherebythe combined spacer 100A and fixation plate 210 may have a reducedheight, and whereupon a reduced sized incision may be used to implantspacer 100A with fixation plate attached. After implantation, fixationplate 210 may be rotated, for example about 90 degrees, so that sockets118 overlie bone of adjacent vertebrae. Rotation may be any amount,however, for example 45 to 135 degrees.

Alternatively, spacer 100A may be implanted without fixation plate 210attached, and through a reduced size incision, with less disturbance tobody tissue. Fixation plate may then be attached to spacer 100A in situ.In this manner, fixation plate 210 may be inserted through the sameentry as spacer 100A, with fixation plate 210 aligned along alongitudinal while being passed through the incision. Once positionedproximate spacer 100A, fixation plate 210 may be reoriented to beattached to spacer 100A, and rotated to align sockets 118 with bone.Rotation of fixation plate 210 can be performed after expansion ofspacer 100A, facilitating alignment of sockets 118 with bone.

It should be understood that the various embodiments described hereinwith respect to spacer 100 and frame 152 may be applied equally tospacer 100A and frame 152A, and any other variants thereof describedherein, and are described separately only to facilitate an understandingof each embodiment. More particularly, various embodiments of thisdisclosure are intended to be combinable in a manner that would beapparent to the practitioner and therapeutic for the patient.

In one embodiment, fixation plate 210 may only be attached to spacer 100when a longitudinal axis of fixation plate 210 is substantially alignedwith a transverse axis of spacer 100, and when fixation plate 210 isrotated to overlie bone, fixation plate 210 is securely affixed tospacer 100. For example, in FIG. 9, an embodiment of interlock 214 isillustrated, including flanges 216 which engage mating flanges 218disposed upon fixation plate 210. Flanges 216, and or the matingflanges, can be ramped or cammed, so that when engaged, fixation plate210 and spacer 100 become progressively more tightly interconnected.

In another embodiment, shown in FIGS. 13-17, fixation plate 210 ispreliminarily held in place using a snap-fit connector 220, functioningto secure fixation plate to spacer 100, or cooperating with interlock216. Snap-fit connector 220 forms at least a preliminary connectionbetween fixation plate 210 and spacer 100, to facilitate handling by themedical practitioner. A plate mounting screw 334 may be connected, forexample threaded into a threaded bore of actuator screw 154, to furthersecure fixation plate 210 to a remainder of spacer 100. Fixation platemay be rotated when connected by snap-fit connector 220. Set screws 226may be passed through apertures 226A to affix fixation plate 210 once ithas been rotated. Snap fit connector 220 comprises extension tangs 222extend from spacer 100, and form a resilient interference fit withsnap-fit aperture 224 upon fixation plate 210. Snap-fit aperture 224 maybe formed upon spacer 100, and extension tangs may extend from fixationplate 210. Additionally, references to spacer 100 should be consideredto include similar embodiments, including spacer 100A.

With reference to FIGS. 16 and 17, fixation plate 210A includes, inanother embodiment of the disclosure, folding or hinged portions 228which may contain sockets for bone screws 300 or other fastener. Wheninserting fixation plate 210A, hinged portions 228 are folded either ona lateral, longitudinal, or other axis of the fixation plate along oneor more hinges 230, as shown in FIG. 11, to reduce a maximum dimensionalprofile of fixation plate 210A. In this manner, fixation plate 210A maypass through a reduced size incision as compared to a requirement for anunfolded fixation plate. In an embodiment, tangs or barbs 232 may extendfrom fixation plate 210 or 210A. to engage body tissue, for examplecortical bone of a vertebra, to provide further fixation and stabilitywhen bone screws are passed through the fixation plate and into bodytissue. Additionally, hinged portions 228 may be angled to permit a bonefastener passed therethrough, for example bone screw 300, to enter boneof the joint at a beneficial or desired angle.

Referring now to FIGS. 18-19, one or more expansion cams 240 aredisposed between endplates 110, 112. A tool is inserted into a socket242 which may be rotated to rotate the cam (as shown by arrows) toseparate endplates 110, 112. Expansion cams 240 can be supported upon ashaft (not shown) connected to frame 152. Endplates 110, 112 can besupported and guided by ramp channels 164A, 168A, as described withrespect to FIG. 5.

Turning now to FIGS. 20-22, in an alternative embodiment, endplates 110,112 include one or more rotating endplate sections 250A, 250B whichengage body tissue to therapeutically increase a height of spacer 100B.In the embodiment shown, two rotating endplates sections areillustrated, each containing a transverse dimension having a firstwidth, and a second longitudinal dimension having a second, greaterwidth. Spacer 100B can be inserted into the body with sections 250A,250B rotated to have a same or lesser height than a remainder of spacer100B, to reduce an incision size, and to fit within an opening formedbetween adjacent vertebrae. After spacer 100B has been positionedbetween vertebrae, sections 250A, 250B may be simultaneously orconsecutively rotated to contact body tissue, for example cortical bone,to distract the joint. Section 250B is disposed on a proximal side ofspacer 100B, and may be rotated by inserting a tool, for example tool252, through or into a mating socket 254, and rotating tool 252.Sections 250A, 250B are rotatably coupled to spacer 100B by a pivotshaft, which may be engaged by tool 252, or by another mating engagementbetween section 250A, 250B and a remainder of spacer 100B, for example aflange (not shown).

Section 250A is inserted first into the body, and to facilitateinsertion, and to reduce interference with body tissue, section 250A maybe rotated so that section 250A and a remainder of spacer 100B form acompressed or unexpanded profile. For example, section 250A is rotatedso that the longest dimension is transverse to an S/I orientation in thebody, and is thus adapted to fit within a space formed between adjacentvertebrae prior to distraction. To distract the joint, tool 252 isinserted into an interior of spacer 100B, and is engaged with a socket254 associated with section 250A, and is rotated to orient section 250Aso that a tallest dimension is aligned with an S/I axis of the patient,distracting the joint.

With reference to FIG. 20, in one embodiment, section 250A fits betweenendplates 110, 112 when rotated in the transverse orientation, tofacilitate insertion between vertebrae. After implantation, section 250Ais pushed distally to emerge from between endplates 110, 112, whereuponit may be rotated to distract, aid in distraction, or maintain aseparation of vertebrae. Tool 252 is connected to section 250A by atether 256, operative to maintain section 250A in contact with aremainder of spacer 100B, in cooperation with a biasing element 258,disposed within tool 252. In FIG. 20, section 250A is illustrated inthree stages of insertion, illustrated by 250A-1, 250A-2, and 250A-3. Inthe first stage, illustrated as 250A-1, tool 252 is engaged with section250A and begins pushing section 250A along an interior of spacer 100Bdefined between endplates 110, 112. In the second stage, illustrated as250A-2, tool 252 has pushed section 250A to an end of an interior ofspacer 100B. In the third stage, illustrated as 250A-3, tool 252 haspushed section 250A to emerge from between endplates 110, 112, whereupontool 252 may then rotate section 250A to orient a long axis of section250 along an S/I orientation within the body. Tether 256 may be securedwithin spacer 100B to maintain section 250A in position at a distal endof spacer 100B. Tool 252 may then be disengaged from spacer 100B andremoved from the patient. FIG. 21 illustrates section 250A orientedtransverse to an S/I orientation, to reduce a height of spacer 100B.FIG. 22 illustrates section 250A rotated to distract or maintain aseparation of vertebra. Projections 260 can be provided, oriented topierce body tissue to foster maintenance of a position of spacer 100within the body.

Referring now to FIGS. 23-24, fixation portions 124, 124A separaterelative to each other as endplates 110, 112 are expanded as describedherein. In this embodiment, fixation portions 124, 124A can slideablymate with an actuating section 208, or may only be affixed to theirrespective endplate 110, 112. One manner of forming a slidable matingconnection is described with respect to FIGS. 31-33, herein. Byremaining in a fixed position relative to their respective endplate 124,124A, portions 124, 124A are properly aligned to secure a fastenerthrough socket 118 into cortical bone of adjacent vertebrae 10, 12.

In FIGS. 25-26, a manner of connecting endplates 110, 112 to fixationportions 124, 124A is illustrated. Fixation portions 124, 124A andendplates 110, 112 are mutually shaped to be mateably connected, forexample by a coupling fastener 262, in this embodiment a screw. In theembodiment shown, endplate 110 and fixation portion 124 are illustrated,however it should be understood that a similar or different connectionmechanism may be employed for endplate 112 and fixation portion 124A.

A similar connection between endplate 110 and fixation portion 124 maybe seen in FIG. 27, in which it may also be seen that screw 300 can becountersunk within fixation plate 124. Socket 118 may additionally be apolyaxial socket, and can include a blocking element 196. FIG. 28illustrates that the in addition to, or in an alternative to the use ofcoupling fastener 262, endplate 110/112 and fixation portion 124/124Amay be joined by shaped coupling, for example a dovetail,tongue-in-groove, or T-connection. As an alternative to couplingfastener 262, an adhesive may be used, or alternatively, the shapedcoupling may produce an interference fit between endplate 110/112 andfixation portion 124/124A. While FIG. 28 illustrates fixation portion124 (or 124A) inserted within endplate 110 (or 112), it should beunderstood that this configuration could be reversed, with endplate110/112 inserted within fixation portion 124/124A.

In FIGS. 29-30, fixation portions 124, 124A swivel so that socket 118can be positioned over cortical bone of a vertebra 10, 12. In theillustration, portions 124, 124A are connected, or are formed as asingle rotating fixation plate 266, and rotate together about a singlepivot. In FIGS. 29-30, the pivot is centrally located about the sameaxis as actuator screw 154, however the pivot may be located elsewhere.In one embodiment, an endplate pivot pin 274 extends between an endplate110/112 and plate 266, causing plate 266 to rotate about the centralaxis as endplate 110/112 is moved with respect to the central axis.Alternatively, as illustrated in FIG. 30A, fixation portions 124, 124Amay be separate, and each pivot on its own pivot, 264, 264A. In thisembodiment, as well as other pivoting embodiments, one or more endplatepivot pins 274 may be provided to cause a controlled rotation of arotatable plate, for example one or both of separated plates 124, 124A.

With reference to FIGS. 31-33, rotating fixation plate 268 is formed intwo slidingly mateable plates 268A, 268B. An exemplary interconnectionbetween plates 268A, 268B is illustrated in FIG. 33, in which a dovetailor interlocking engagement 270 may be seen. In this embodiment,interlocked plates 268A, 268B are secured in connection with a remainderof spacer 100, and rotate about, a pivot 272. In one embodiment, pivot272 is associated with actuator screw 154. In a related embodiment,rotation of actuator screw 154 causes a rotation of plate 268 due to amechanical connection between actuator screw 154 and plate 268. Inanother embodiment, pivot 272 is formed coaxial with, but separate fromactuator screw 154.

Referring now to FIG. 34-35, blades, spikes, pins, or piercing elements276 are disposed within piercing guides 278 formed within spacer 100,for example within endplates 110, 112. Only relevant portions of spacer100 are illustrated in FIGS. 34-35, to clarify this feature of thedisclosure. In one form, piercing element 276A passes through a portionof ramp 164, and is pushed by ramp 168 as actuator screw 154 is rotatedto engage mating ramps 164, 168. Piercing element emerges throughendplate 110 or 112 to pierce body tissue, for example cancellous orcortical bone of adjacent vertebrae 10, 12. In this manner, spacer 100is further affixed in a therapeutic location within the body. Byproviding additional fixation in the form of piercing elements 276,spacer 100 is better adapted to function without supplemental support,as a standalone device, without for example other fixation or fusingdevices. Additionally, piercing elements herein can provide sufficientfixation so that a fixation portion 124, 124A can optionally beeliminated, and fixation exterior to the intervertebral space may beavoided.

In another embodiment shown in FIGS. 34-35, piercing element 280 isformed as a resilient curved member which is straightened as it ispushed by a portion of carriage 156. During straightening, piercingelement 280 elongates to pass through endplate 110, 112 to pierce bodytissue.

In FIGS. 36-37, bone screw 300A is formed with gear teeth 282 disposedto lie along a longitudinal axis of the screw, as well as standard boneengaging threads substantially transverse to this longitudinal axis.Actuator screw 154A includes external gear teeth 284 mateable with gearteeth 282 of bone screw 300A, whereby when either bone screw 300A oractuator screw 154A is rotated, endplates 110, 112 separate to increasea height of spacer 100, and bone screw 300A is simultaneously driveninto body tissue to therapeutically secure implant 100 to bone.

FIGS. 38-40 illustrate a method of connecting endplate 110/112 tofixation portion 124/124A, using a mortise and tenon or dovetailconnection 286. A keyed aperture 288 disposed within fixation portion124 or endplate 110 mateably receives a correspondingly shapedprojection 290 in the other of fixation portion 124 and endplate 110. Asimilar connection may be formed between fixation portion 124A andendplate 112. Aperture 288 and projection 290 may form an interferencefit, or may alternatively be secure in mating conformity using a setscrew or adhesive, for example.

With reference to FIG. 41, it may be seen that one or both of endplate110, 112 may be beveled, truncated, fenestrated, or shaped with a gap,groove, or channel 292 in endplate 110, 112, dimensioned to permitpassage of a bone screw 300, whereby a maximum height of spacer 100,with the exception of bone screw 300, is defined by an expanded heightof endplates 110, 112. Channel 292 can allow passage of a shank 294, orany other portion of bone screw 300 or other fastener, so that socket118 does not lie at a height greater than an endplate 110, 112.

Turning now to FIGS. 42-44, an embodiment of the disclosure includes oneor more piercing elements 276A, pivotally mounted to rotatable deployers310. Piercing elements 276A may have any shape which is adapted topierce, grip, or engage body tissue, including pin, spike, or bladeconfigurations. Although drawn as separate blades in FIG. 42, it shouldbe understood that elements 276A may extend along a substantial lengthof a longitudinal axis of spacer 100, and may be supported by one, two,or more deployers 310. An axle, pin, or shaft 296 pivotably mountsdeployer 310 to frame 152, carriage 156, or other mounting point ofsuitable strength, upon spacer 100, so that deployers 310 may rotateabout a longitudinal axis aligned with a longitudinal axis of spacer100, although mounting along a different axis can be provided. In FIGS.42-44, spacer 100 is illustrated without endplates 110, 112 andassociated ramps, to simplify the illustrations. It may be seen,however, that ramps 164, 168 may be reduced in size to allow room forone or more deployers 310.

In use, a tool (not shown) is engaged with an engagement port 198 and isrotated to rotate a deployer 310, to advance piercing element 276Athrough an opening or gap in an endplate 110/112. In one embodiment,piercing element 276A is fixed to an end of deployer 310, and entersbody tissue at an angle with respect to a plane defined by an endplate110/112. In the embodiment shown, piercing element is pivotally mountedto deployer 310 at pierce pivot 312, and can be guided, for example byguide 314, which may be a shaped channel in endplate 110/112, to enterbody tissue, for example bone of a vertebra 10/12, substantiallyperpendicular to a plane defined by an endplate 110/112, or at aparticular desired angle or within a range of angles. Piercing elements276A therapeutically secure implant 100 to bone or body tissue of thejoint.

FIGS. 45-47 contain elements analogous to FIGS. 42-44, however deployer310 rotates about a common axis with actuator screw 154, and thereforerelatively larger ramps 164, 168 can be maintained. Piercing elements276B may further be longer, as a length of an arm 316 of deployer 310Amay be longer.

In FIG. 48, a collar 320 is connected to deployer 310A, and rotatesabout a common axis with actuator screw 154, but may be rotatedindependently of actuator screw 154 using tool engagement port 322. Inanother embodiment, actuator screw is directly connected to deployer310A, and causes deployment of piercing elements 276A as endplates 110,112 are expanded as described herein. In a yet further embodiment,actuator screw rotates deployer 310A through a gear reduction (notshown), whereby deployer 310A rotates about the common axis more slowlythan actuator screw 154, so that increased leverage may be applied topiercing elements 276A.

With reference to FIG. 49, in an embodiment of the disclosure, endplates110, 112 can pivot about an axis 324 extending transverse to alongitudinal axis of spacer 100, or along an axis that extends along anS/I direction when spacer 100 is implanted within a patient. Forexample, one or more pivot pins 326 may extend from an endplate 110 toframe 152, or may extend from endplate 110 to endplate 112. In thismanner, spacer 100 may accommodate an additional rotational degree offreedom, for example, spacer 100 may support six degrees of freedom ofmovement of adjacent vertebrae. This is accomplished in one embodimentby enabling movement of ramped surfaces 164, 168 with respect to eachother, thereby enabling roll, pitch, and yaw of endplate 110/112 withrespect to frame 152. While rotation about this axis is explicitlysupported in this embodiment, it should be understood that allembodiments herein can be configured to support rotation about axis 324,as well. A rotating fixation plate, for example fixation plate 266, canbe provided in this embodiment, as with other embodiments of thedisclosure.

Implants of the disclosure enable a continuous expansion and retractionover a range of displacements according to predetermined dimensions of aspecific spacer 100 design. This provides the ability to distractvertebral bodies to a desired height, but also to collapse the spacer100 for repositioning, if therapeutically advantageous for the patient.Endplates 110, 112 may be shaped to form planes or surfaces whichconverge relative to each, to provide for proper lordosis, coronalcorrection, or kyphosis and can be provided with openings through whichbone may grow, and into which bone graft material may be placed. Spacer100 may be used to distract, or force bones of a joint apart, or may beused to maintain a separation of bones created by other means, forexample retractor. Endplates 110, 112 may additionally be curved toconform to the surface of body tissue, for example the surface ofcortical bone, of the vertebra to be contacted, for improved fixationand load bearing.

Spacer 100 may be fabricated using any biocompatible materials known toone skilled in the art, having sufficient strength, flexibility,resiliency, and durability for the patient, and for the term duringwhich the device is to be implanted. Examples include but are notlimited to metal, such as, for example titanium and chromium alloys;polymers, including for example, PEEK or high molecular weightpolyethylene (HMWPE); and ceramics. There are many other biocompatiblematerials which may be used, including other plastics and metals, aswell as fabrication using living or preserved tissue, includingautograft, allograft, and xenograft material.

Portions or all of the implant may be radiopaque or radiolucent, ormaterials having such properties may be added or incorporated into theimplant to improve imaging of the device during and after implantation.

For example, metallic portions 124, 124A of endplates 110, 112 may bemanufactured from Titanium, or a cobalt-chrome-molybdenum alloy,Co—Cr—Mo, for example as specified in ASTM F1537 (and ISO 5832-12). Thesmooth surfaces may be plasma sprayed with commercially pure titanium,as specified in ASTM F1580, F1978, F1147 and C-633 (and ISO 5832-2).Polymeric portions 122, 122A may be manufactured from ultra-highmolecular weight polyethylene, UHMWPE, for example as specified in ASTMF648 (and ISO 5834-2). In one embodiment, PEEK-OPTIMA (a trademark ofInvibio Ltd Corp, United Kingdom) may be used for one or more componentsof spacer 100. For example, polymeric portions 122, 122A can be formedwith PEEK-OPTIMA, which is radiolucent, whereby bony ingrowth may beobserved. Other polymeric materials with suitable flexibility,durability, and biocompatibility may also be used.

In accordance with the invention, implants of various sizes may beprovided to best fit the anatomy of the patient. Components of matchingor divergent sizes may be assembled during the implantation procedure bya medical practitioner as best meets the therapeutic needs of thepatient, the assembly inserted within the body using an insertion tool.Implants of the invention may also be provided with an overall angulargeometry, for example an angular mating disposition of endplates 110,112, to provide for a natural lordosis, or a corrective lordosis, forexample of from 0° to 6° for a cervical application, although muchdifferent values may be advantageous for other joints. Lordotic anglesmay also be formed by shaping one or both of plates 110, 112 to haverelatively non-coplanar surfaces. Expanded implant heights, for use inthe vertebrae for example, may typically range from 3 mm to 25 mm, butmay be larger or smaller, including as small as 2 mm, and as large as 30mm, although the size is dependent on the patient, and the joint intowhich an implant of the invention is to be implanted. Spacers 100 may beimplanted within any level of the spine, and may also be implanted inother joints of the body, including joints of the hand, wrist, elbow,shoulder, hip, knee, ankle, or foot.

In accordance with the invention, a single spacer 100 may be used, toprovide stabilization for a weakened joint or joint portion.Alternatively, two, three, or more Spacers 100 may be used, at a singlejoint level, or in multiple joints. Moreover, Spacers 100 may becombined with other stabilizing means.

Additionally, spacer 100 may be fabricated using material thatbiodegrades in the body during a therapeutically advantageous timeinterval, for example after sufficient bone ingrowth has taken place.Further, spacer 100 is advantageously provided with smooth and orrounded exterior surfaces, which reduce a potential for deleteriousmechanical effects on neighboring tissues.

Any surface or component of the invention may be coated with orimpregnated with therapeutic agents, including bone growth, healing,antimicrobial, or drug materials, which may be released at a therapeuticrate, using methods known to those skilled in the art.

Devices of the disclosure provide for adjacent vertebrae to be supportedduring flexion/extension, lateral bending, and axial rotation. In oneembodiment, spacer 100 is indicated for spinal arthroplasty in treatingskeletally mature patients with degenerative disc disease, primary orrecurrent disc herniation, spinal stenosis, or spondylosis in thelumbosacral spine (LI-SI). Degenerative disc disease is advantageouslydefined as discogenic back pain with degeneration of the disc confirmedby patient history and radiographic studies, with or without leg(radicular) pain. Patients are advantageously treated, for example, whomay have spondylolisthesis up to Grade 2 at the involved level. Thesurgery position spacer 100 may be performed through an Anterior,Anterolateral, Posterolateral, Lateral, and/or posterior approach.

In a typical embodiment, spacer 100 has a uncompressed height, beforeinsertion, of 2 to 25 mm, and may advantageously be provided incross-sections of 23×32 mm, 26×38 mm and 26×42 mm, with 4, 8, 12, or 16degree lordotic angles, although these are only representative sizes,and substantially smaller or larger sizes can be therapeuticallybeneficial. In one embodiment a spacer 100 in accordance with theinstant disclosure is sized to be inserted using an MIS approach (areduced incision size, with fewer and shorter cuts through body tissue).

Spacer 100 may advantageously be used in combination with other known orhereinafter developed forms of stabilization or fixation, including forexample rods and plates.

FIG. 50 illustrates an exploded view of an alternative spacer deviceaccording to some embodiments. The device 400 comprises a number ofcomponents similar to the device 100 described above, including a spacerportion 422 and a fixation portion or plate portion 424. The spacerportion 422 comprises a frame or body 452 for receiving a carriage ortranslation member 456 therein, an upper endplate 410, a lower endplate412, and an actuator screw or member 454 for moving the translationmember 456 to expand or contract the distance of separation between theendplates. The spacer portion 422 is operably attached to at least oneplate portion 424 comprising a bone screw opening 421 for receiving abone screw (not shown) for insertion into a bone member and a blockingscrew opening 420 for receiving a blocking screw 419. With the combinedspacer portion 422 and plate portion 424, the device 400 canadvantageously serve as a standalone spacer that can be inserted througha number of approaches, including laterally, posteriorly or anteriorly.

In addition to the features described above, device 400 also includes anumber of unique features designed to provide a number of differentadvantages. Among the novel features include: screws 409 designed tosecure the spacer portion 422 to the plate portion 424 for enhancedconnection; wrap-around portions 417, 418 extending from the upper andlower endplates 410, 412 for enhanced connection; rod extensions 484extending from the body of the translation member 456 that penetrateinto the plate portion 424 for increasing the strength of the device 400in tension; mating slots 489 (e.g., T-slots or dovetail slots) formed inthe translation member 456 for receiving a complementary mating featurein an upper or lower endplate 410, 412 for improved integration; theaddition of a c-clip or spring clip 480 to the actuation member 454 tosecurely hold the actuation member 454 in position relative to thetranslation member 456; the addition of a PEEK washer 457 in between theinterface of the translation member 456 and actuation member 454 toprevent metal-on-metal contact; and a device design with an open centerthat provides for back fill with bone graft, whether the device is in acompressed or expanded state. These features will be discussed in moredetail below.

As shown in FIG. 50, the spacer device 400 is comprised of a spacerportion 422 including a body 452, translation member 456, upper endplate410, lower endplate 412 and actuation member 454. The spacer portion 422is attachable to one or more plate portions 424, including one or morebone screw openings 421, blocking screw openings 420 and rod receivingbores 423. In the present embodiment, the spacer portion 422 isattachable to an upper plate portion 424A and a lower plate portion424B. In some embodiments, while the spacer portion 422 is insertableinto a vertebral space between vertebral bodies, the plate portions424A, 424B are capable of receiving bone screws that penetrate bone tomake the device 400 a standalone spacer device.

Further details regarding the spacer portion 422 will be discussedherein. The spacer portion 422 comprises a frame or body 452 forreceiving a translation member 456 therein. The body 452 includes a pairof sidewalls separating a front portion and a rear portion. As shown inFIG. 50, each of the sidewalls includes a side slot 431 for receiving asupport screw 474 therein. Each of the support screws 474 is configuredto extend into a support screw opening 465 formed in the translationmember 456, thereby attaching the body 452 to the translation member456. The front portion of the body 452 includes a pair of openings 451for receiving one or more stabilizers 459 therein. Advantageously, thestabilizers 459 are configured to help stabilize the translation member456 in the central opening of the body 452. The rear portion of the body452 includes an opening 453 for receiving an actuation member (e.g.,screw) 454 for moving the translation member 456. Advantageously, theopening 453 can serve as a backfill opening whereby bone graft materialor other material is received through the opening 453, regardless ofwhether the device 400 is in an expanded or contracted state. While inthe present embodiment the opening 453 remains open, even afterimplantation, in other embodiments, the opening 453 can be closed off.

The translation member 456, which is received in the body 452, includesone or more ramps for engaging with ramps on corresponding endplates. Asthe translation member 456 moves or translates laterally, ramps on thetranslation member 456 engage corresponding ramps on endplates, therebycausing expansion and/or contraction of the device. As shown in FIG. 50,in some embodiments, the translation member 456 includes three pairs oframps 466, 468, 470 extending upwardly from the body of the translationmember 456, as well as three pairs of ramps extending downwardly fromthe body of the translation member 456. Ramp 466 is separated from ramp468 by a first bridge member 467, while ramp 468 is separated from ramp470 by a second bridge member 467. As the translation member 456 moveslaterally, the three pairs of upwardly extending ramps on thetranslation member 456 engage and interact with downwardly facing rampsof the upper endplate 410, while the three pairs of downwardly extendingramps engage and interact with upwardly facing ramps of the lowerendplate 412, thereby causing expansion or contraction of the device.Advantageously, the three pairs of ramps are located along the peripheryof the upper and lower surfaces of the translation member 456, therebyleaving a central area of the translation member 456 completely exposedand capable of receiving bone graft or other material therein. While thepresent embodiment includes the translation member 456 as having threepairs of ramps on an upper surface and a lower surface of thetranslation member, in other embodiments, the translation member canhave one, two or four or more pairs of ramps on either the upper surfaceor lower surface of the translation member.

The front portion of the translation member 456 includes one or moremating slots 489 (best shown in FIG. 51) on upper and lower surfaces ofthe translation member 456 for receiving corresponding mating featureson the upper and lower endplates 410, 412. In some embodiments, themating slots 489 comprise T-slots or dovetail slots. These mating slots489 advantageously hold the endplates 410, 412 on the translation member456, thereby improving the connection between the translation member 456and the endplates 410, 412.

The rear portion of the translation member 456 includes an opening 455for receiving a washer 457 and an actuation member 454 therein. In someembodiments, the washer 457 comprises a PEEK washer, and isadvantageously inserted between the interface of the translation member456 and the actuation member 454, thereby preventing metal-on-metalcontact. In addition, the rear portion of the translation member 456also includes one or more rod extensions 484 (e.g., or bar extensions orother shaped extensions) that extend from a body of the translationmember. These novel rod extensions 484 are capable of being receivedthrough corresponding rod receiving bores 423 in the plate portions 424.As such, the rod extensions 484 advantageously hold the plate portions424 such that when the plate portions are in tension, the overall systemhas greater strength. While in the present embodiment, the translationmember 456 includes a pair of upper rod extensions angled upwardly and apair of lower rod extensions angled downwardly, in other embodiments,the translation member 456 can include a single upper rod extension orlower rod extension, or three or more upper rod extensions or lower rodextensions.

An upper endplate 410 is operably attached to an upper surface of thetranslation member 456. The upper endplate 410 comprises a texturedupper surface having one or more teeth, ridges, ribs, etc. designed toengage an upper vertebral body. Graft windows 432 and 433 are formedthrough the upper surface of the upper endplate 410, and allow for bonegrowth material to pass therethrough. As shown in FIG. 50, while graftwindow 432 is completely enclosed on four-sides by surfaces of theendplate, graft window 433 has an exposed side that is ultimately closedby the plate portion 424. Advantageously, these graft windows 432, 433are in open communication with the central portion of the translationmember 456, which is open and available to receive backfilled graftmaterial or other material therein.

Upper endplate 410 further includes wrap-around portions 417 that extenddownwardly from the side sections of the upper endplate 410. Thesewrap-around portions 417 cover portions of the translation member,thereby advantageously providing a secure interface between thetranslation member and the endplates, which helps provide strength tothe device, particularly when it is placed in tension.

Rear portion of the upper endplate 410 also includes one or moreopenings 406 for receiving screws 409 therein. The screws 409 aredownwardly inserted, and are configured to be inserted through the upperendplate 410 and an upper plate portion 424A to advantageously securethe upper endplate and the upper plate portion together. As shown inFIG. 50, the upper endplate 410 can receive a pair of screws 409.However, in other embodiments, one, three, four or more screws can bereceived to securely integrate the upper endplate 410 with the upperplate portion 424A.

A lower endplate 412 is operably attached to a lower surface of thetranslation member 456. The lower endplate 412 shares similar featureswith the upper endplate 410, including surface texturing, graft windows,wrap-around portions 418, and openings for receiving a pair of screws409. The screws 409 in the lower endplate 412 are configured to beinserted through the lower endplate 412 and a lower plate portion 424Bto advantageously secure the lower endplate 412 and the lower plateportion together.

An actuation member 454 is inserted into the rear opening 455 of thetranslation member 456 and is operably attached to the translationmember 456. The actuation member 454 comprises an actuation screwwhereby rotation of the member 454 in one direction causes translationof the translation member 456 in a first direction, thereby causingexpansion of the device 400. Reverse rotation of the actuation screwcauses translation of the translation member 456 in on oppositedirection, thereby causing contraction of the device 400. To secure theactuation member 454 to the translation member 456, the actuation member454 can be accompanied by a c-clip or spring clip 480 that is attachedto a front portion of the actuation member 454. With reference to FIG.52, as the actuation member 454 is moved laterally, the spring clip 480can compress under a notch 491 formed in the translation member 456 andcan spring into a desired recess 493 formed in the translation member456, thereby advantageously securing the actuation member 454 to thetranslation member 456. In some embodiments, the actuation member 454can include a lock nut or friction nut 499 that forms around theactuation member to stabilize and control the actuation member duringrotation.

In the present embodiment, the spacer portion 422 is advantageouslyconnected to an upper plate portion 424A and a lower plate portion 424B.The upper plate portion 424A is configured to receive a screwtherethrough to fix the upper plate portion 424A to an upper vertebra,while the lower plate portion 424B is configured to receive a screwtherethrough to fix the lower plate portion 424B to a lower vertebra.The upper and lower plate portions are described below.

The upper plate portion 424A comprises an opening 421A for receiving abone screw therethrough for securing the upper plate portion 424A to anupper vertebra. In addition, the upper plate portion 424A comprises ablocking screw opening 420A for receiving a blocking screw 419Atherethrough to prevent inadvertent back-out of the bone screw. In someembodiments, the blocking screw 419A is pre-attached to the upper plateportion 424A prior to inserting a bone screw therethrough. As shown inFIG. 50, the blocking screw 419A can include a cut-away portion 416A.When the cut-away portion 416A is adjacent the bone screw opening 421A,this allows entry of a bone screw therethrough. After the bone screw hasbeen inserted through the bone screw opening 421A, the blocking screw419A can be rotated to block and prevent the bone screw frominadvertently backing out. In some embodiments, the blocking screw 419Acovers an upper surface of an inserted bone screw, while in otherembodiments, the blocking screw 419A presses firmly against a side of ahead of the bone screw, to thereby prevent backing out of the screw. Inaddition, the upper plate portion 424A further includes novel rodreceiving bores 423A for receiving the rod extensions 484 of thetranslation member 456, thereby providing a secure connection betweenthe upper plate portion 424A and the translation member 456.

The lower plate portion 424B comprises similar features as the upperplate portion 424A, including an opening 421B for receiving a bone screwtherethrough, a blocking screw opening 420B for receiving a blockingscrew 419B therethrough, and rod receiving bores 423B for receiving rodextensions 484 of the translation member 456. In some embodiments, boththe upper plate portion 424A and the lower plate portion 424B areattached to the upper endplate 410 and lower endplate 412, respectively,via screws 409. In some embodiments, while the spacer device 400includes both an upper plate portion 424A and a lower plate portion424B, in other embodiments, the spacer device 400 can include only oneof the plate portions.

FIG. 51 illustrates a top perspective view of the alternative spacer ofFIG. 50 with upper endplate removed. From this view, one can see how theactuation member 454 is attached to the translation member 456. As theactuation member 454 is rotated in one direction, the translation membercan translate laterally in a first direction, thereby causing expansionof the device 400. As the actuation member 454 is rotated in theopposite direction, the translation member can translate laterally in asecond direction opposite from the first, thereby causing contraction ofan expanded device 400.

From the view in FIG. 51, one can also view the various features of thetranslation member, including the three pairs of upper ramps 466, 468,470, the bridges 467 separating the ramps, and the rod extensions 484.In addition, one can view the mating slot 489, which is formed betweenramps 466 on a front portion of the translation member.

FIG. 52 illustrates a side cross-sectional view of the alternativespacer of FIG. 50. From this view, one can see how the actuation member454 is attached to the translation member 456 via the spring clip 480.As shown in the figure, the spring clip 480 of the actuation member 454is pushed under a notch 491 of the translation member 456, whereby itresides within a recess 493. In addition, from this view, one can seehow the device 400, in some embodiments, can include a tapered nose 411to assist with distraction and insertion of the device 400 into adesired disc space.

FIG. 53 illustrates a different cross-sectional view of the alternativespacer of FIG. 50. In this cross-sectional view, one can see theintegration of the support screw 474 within the device 400, whichadvantageously helps to connect and stabilize the different components.

FIGS. 54A and 54B illustrate a rear view of the alternative spacer ofFIG. 50. FIG. 54A illustrates the spacer device 400 in a collapsedconfiguration, while FIG. 54B illustrates the spacer device 400 in anexpanded configuration. In some embodiments, as the actuation member 454is rotated in a first direction, the translation member 456 translateslaterally, such that its ramps interact with ramps on correspondingendplates, thereby causing the endplates to separate from one another.This brings the device 400 from a collapsed state to an expanded state.As the upper endplate 410 is attached to an upper plate portion 424A,and the lower endplate 412 is attached to a lower plate portion 424B,movement of the endplates causes movement of the plate portions. Whenthe device is in the expanded configuration, as shown in FIG. 54B,bottom posts 428A of the upper plate portion 424A can be exposed, whiletop posts 428B of the lower plate portions 424B can be exposed.

FIG. 55 illustrates a top cross-sectional view of the alternative spacerof FIG. 50. From this view, one can see how the translation member 456includes an open central portion, whereby graft material can be filledpacked into the device whether it is in a contracted configuration or anexpanded configuration. The spacer device 400 provides easy accessthrough the actuation member 454 should one want to provide bone graftor other material into the center of the translation member 456.

FIG. 56 illustrates a close-up cross-sectional view of the actuationmember and translation member of the alternative spacer of FIG. 50. Fromthis view, one can see how the translation member 456 and the actuationmember 454 are joined together. As noted above, a c-spring or clip 480can be attached to an external surface of the actuation member 454. Asthe actuation member 454 is forced laterally into the translation member456, the clip 480 can be forced under a notch 491 in the translationmember 456 until it resides in recess 493. From FIG. 56, one can alsosee how the translation member 456 includes angulated funnel surfaces497. These funnel surfaces 497 advantageously guide and compress theclip 480 until it is forced under the notch 491.

FIGS. 57-60 illustrate spacer 500, which may be consistent with thespacers previously described herein including spacer 100 and 400. Spacer500 may have the same or similar components as previously described.Spacer 500 may include endplates 502 and 504 and one or more anchors506. Anchors 506 may be used as an alternative to bone screws in orderto attach the spacer to the patient. Anchors may be used because incertain conditions the angle at which a bone screw may be inserted couldinterfere with a patient's anatomy such as soft tissue or the iliaccrest. Anchors may be used and, in particular curved anchors, asdescribed in greater detail below to minimize damage to the patientduring a procedure.

Spacer 500 may be operative, when positioned between adjacent bones of ajoint, such as for example vertebrae 10, 12 (shown in FIG. 7), tostabilize a joint formed between adjacent vertebrae. Spacer 500 has acollapsed state or height or an expanded state or height as previouslydescribed herein.

Spacer 500 may be inset into the intervertebral disc space at acollapsed height, and then expand axially (superior/inferior) to restoreheight loss in the disc space. Spacer 500 provides distraction as wellas achieves optimal separation of adjacent vertebrae, or disc heightrestoration. When inserted in a collapsed state, spacer 500 may have areduced height profile which reduces adverse impact to tissue adjacentto and within the joint space during insertion, while presenting theleast visually blocking or physically obstructing profile. Spacer 500may be reduced in height after implantation, for example by inserting atool through a minimal incision, to perform a therapeutic heightadjustment. Spacer 500 may also be reduced in height to a compressedconfiguration, to facilitate removal from the body. Spacer 500 supportsthe cortical rim of adjacent vertebrae, and distributes forces acrossthe vertebra, thereby maximizing vertebral endplate preservation.

Spacer 500 includes two separable endplates 502 and 504. A surface 508of an endplate 502, 504 can be provided with teeth or other projections510 which can penetrate body tissue to reduce a likelihood of migrationof spacer 500 after implantation. Spacer 500 is further secured with oneor more fasteners, such as anchors 506, which pass through an adapter,such as socket 512 within spacer 500, and into body tissue of thepatient. Two sockets 512 may be provided for two anchors 506, althoughone or more than two fasteners and fastener adapters, may be provided.Anchors 506 can be retained in connection with spacer 500 by blockingfasteners 514. In some embodiments, the adapters or sockets can beintegrated with the spacer. In other embodiments, a coupling member,such as a set screw, can be configured to couple the adapter to thespacer. In yet other embodiments, the adapters may not be engaged withthe spacer.

As shown in FIGS. 61A-C, anchors 506 may be have a spherical head 516.The portion of anchor 506 that is inserted may be curved and may bet-shaped with sharp edges to cut into the bone of the patient. Anchor506 may have serrated edges to aid insertion into the bone and may alsoaid in restriction expulsion of anchor 506. Anchor 506 is depicted asbeing curved, however, anchor 506 may be straight or helical and beconsistent with the principles of the present disclosure.

All references cited herein are expressly incorporated by reference intheir entirety. There are many different features to the presentinvention and it is contemplated that these features may be usedtogether or separately. Unless mention was made above to the contrary,it should be noted that all of the accompanying drawings are not toscale. Thus, the invention should not be limited to any particularcombination of features or to a particular application of the invention.Further, it should be understood that variations and modificationswithin the spirit and scope of the invention might occur to thoseskilled in the art to which the invention pertains. Accordingly, allexpedient modifications readily attainable by one versed in the art fromthe disclosure set forth herein that are within the scope and spirit ofthe present invention are to be included as further embodiments of thepresent invention.

What is claimed is:
 1. An orthopedic device for a patient comprising: aspacer comprising: a body member; a translation member received in thebody member, the translation member including at least one upper rampportion and one lower ramp portion; an upper endplate having at leastone lower ramp for engaging the upper ramp portion of the translationmember; a lower endplate having at least one upper ramp for engaging thelower ramp portion of the translation member; an actuation memberoperably connected to the translation member, whereby rotation of theactuation member in a first direction causes the translation member tomove in a first direction, thereby causing the distance of separationbetween the upper endplate and the lower endplate to increase; and afirst socket; and a first anchor configured to fasten the spacer to thepatient, wherein the first anchor is received in the first socket. 2.The device of claim 1, wherein the first socket is attached to the upperendplate.
 3. The device of claim 2, further comprising a second anchorto fasten the spacer to the patient and wherein the spacer furthercomprises a second socket, attached to the lower endplate, configured toreceive the second anchor.
 4. The device of claim 3, wherein at leastone of the first anchor and the second anchor is curved and configuredto pierce a bone of the patient to fasten the spacer to the patient. 5.The device of claim 4, wherein at least one of the first anchor and thesecond anchor is configured to have a t-shaped cross-section and sharpedges to pierce the bone of the patient to fasten the spacer to thepatient.
 6. An orthopedic device for a patient comprising: a spacercomprising: a body member; a translation member received in the bodymember; an upper endplate configured to engage the translation member; alower endplate configured to engage the translation member; an actuationmember operably connected to the translation member, whereby operationof the actuation member causes the upper endplate and the lower endplateto move in a direction away from the translation member; and a firstsocket; and a first anchor configured to fasten the spacer to thepatient, wherein the anchor is received in the first socket.
 7. Thedevice of claim 6, wherein the first socket is attached to the upperendplate.
 8. The device of claim 7, further comprising a second anchorto fasten the spacer to the patient and wherein the spacer furthercomprises a second socket, attached to the lower endplate, configured toreceive the second anchor.
 9. The device of claim 8, wherein at leastone of the first anchor and the second anchor is curved and configuredto pierce a bone of the patient to fasten the spacer to the patient. 10.The device of claim 9, wherein at least one of the first anchor and thesecond anchor is configured to have a t-shaped cross-section and sharpedges to pierce the bone of the patient to fasten the spacer to thepatient.